Cutlery grinder



April 13, 1937. '-N. H. ADAMS 2,077,195

CUTLERY GRINDER Filed July 12, 1954 Patented Apr. 13, 1937 Nathan H. Adams s New York chenectad y I to General Electric Companygacorpmatiorljpfi Application July ,12, 1934, Serial No. 734,778

2 Claims.

My invention relates to grinders and more particularly to an improved motor driven cutlery grinder for household and'other uses.

One object of my invention is to provide a motor driven grinder which will be safe for household use.

Another object of my invention is to provide a guide slot having its sides at different angles to the grindstone so that each side respectively may be used for guiding tools having cutting edges at different angular relation to the guiding sides, such, for example, as knivesand scissors.

Another object of my invention is to provide a grinder in which the grindstone is self-dressing.

In the accompanying drawing, Fig. 1 illustrates a side view, partly in section, of a grinder built in accordance with my invention; Fig. 2 illustrates'a top view thereof, also partly insection; Fig. 3 is a vertical sectional view looking in direction of the arrow on line 3-3 in Fig. 1; Fig. 4 is a perspective view of the guiding member, and Fig. 5 is a modification of the guiding member.

Referring to the drawing in detail, Fig. 1 illustrates an electric motor, the windings and magnetic core of which are not shown and form no part of this invention, enclosed'in a casing 5, having a base 6 and a sleeve section 1 at the top. The motor is provided with a shaft 8 which is guided by an upper bearing 9 and a lower bearing Ill. The lower bearing is mounted in the end wall H of the casing 5. The thrust of the shaft 8 is taken up by a ball I2 resting on a plate l3 in a recess 14 provided in the end wall I I.

On the upper end of shaft 8 a collar I5 is mounted by means of a set screw "5. A grindstone IT in the form of a ring is cemented to this collar. The collar is mounted on the shaft in a position such that the stone I! will project partly above the end of sleeve 1. The sleeve I is threaded on the outer side to receive a cap or guiding member l8, which is a cover for the sleeve and encloses the stone. I,

The cap I8 is a cup-shaped member provided with a pair of parallel slots l9 and 20. These slots are spaced slightly from the axis of the stone so that they are substantially radial with respect to the stone. Each slot is bounded by sides 2| and 22. Theside 22 being at a slight angle to the vertical is designed to guide the inner edge of scissors and the side 2| is at a slight angle to the horizontal which is the proper angle at which to guide knives. The slots do not extend across the entire diameter of the cap IS. The material of the cap is cut away at each end of the slots and at right angles thereto leaving the surfaces 23 and 24 within a short distance of the edge of the stone I1 and thereby permit ting the guiding of the knives and scissors within a short distance of the handle or, in the case of scissors, within a short distance of the pivot pin. This cutting of the cap leaves a cross bar 25 at the top to cover the stone. This bar isprovided 5 with a lug 26 attached thereto in a manner'to project into the center of thegrindstone. This lug prevents the drawing of the point of a knife in under the bar 25 when the stone is operating at high speed.

Another important feature in the use of grind-- stones is the provision of means to keep the grinding surface flat. This is generally accomplished '7 equally. The term used for flattening a grindstone surface is dressing. In the apparatus described this is done automatically and we may say for convenience that the grindstone is selfdressing. I accomplish thisautomatic dressing by raising the one'end ofthe guide slot whereby Y the slot is tilted at a slight angle to the horizontal plane of rotation off'thel grinding wheel so that the edge to be ground will contact the grinding wheel on only one side of the axis of rotation as clearly illustrated in Fig. 3. The grinding sur- 30 face is also tilted somewhat'so as to be parallel to the guide surface. As the cutting edge is a guided overthe surface, it ls guided substantially I parallel to this surface and thereby wears off the grinding surface equally wherefore separate resurfacing operations become unnecessary.

The cap I8 is adjusted with'respect-to the grinding surface by merely turning the cap on the sleeve and looking it in place bymeans of the locking ring 21. In Fig. 5 I have shown a 40 modification wherein the cap is simply slipped over the sleeve 1 and. is locked thereto by a screw 28. A slanting slot 29 in .the cap provides for 7 an adjustment of'the cap and guide slots with respect to, the grindstone'surface.

Although I have described my invention in connection with the grinding of knives and scissors, it will be clear to those skilled inthe art that it may be applied to the. grinding of any edged" tool. The knife and scissors illustrate merely two types of cutting edges, the scissors being I the shearingedge and the knife the slicing edge. By merely selecting the proper angles to the two sidesof the guiding slot, the grinder maybe 2 adapted for the grinding of any typeoi' cutting edge or it may be used merely for grinding any surface at a predetermined'ans'u ar relation to a second surface.

' What I "claim as new and desire to secure by Letters Patent of the United States is:.

1. In a cutlery grinding apparatus, .the combination of a-motor provided with a casing, and

a shaft projecting therefrom, a grinding wheel mounted on said shaft, an adjustable cover for said casing and wheel provided with a guide slot arranged substantially radially to said grinding wheel and provided with two sidesyeach of which is arranged at a predetermined angle to the wheel r mounted. on} said projecting shaf and v r for said casing enclosing saidgrindstone and provided'with a guide slot having-sides arranged "angularly with respect to said grindstone, the angular relations 0! said sides being selected for guiding'tools having shearing and slicing edges respectively. a I

. NATHAN H. ADAMS. 

